The objective of this proposal is to establish and maintain a specific- pathogen-free (SPF) rhesus macaque supply and breeding colony program at the Sabana Seca Field Station (SSFS) of the Caribbean Prima Research Center (CPRC). This program will use genetically-characterized, MHC- typed, Indian-origin monkeys from the CPRC's free-ranging colony on the island of Cayo Santiago (CS). The CPRC will donate the founding stock for the colony from its Cayo Santiago and Cayo Santiago-derived populations. Previous surveys have shown that the CS macaques are free of several important viruses including retroviruses and simian virus 40 (SV-40), and that the majority of immature animals are negative for B- virus (Herpesvirus simiae Cercopithecine herpesvirus type 1). About 20- 25% of these monkeys are also Mamu-A*01 positive. Currently there is a shortage of SPF rhesus monkeys for biomedical research and the demand for these animals expected to increase dramatically in the future. The establishment and maintenance of this program at 551 will help meet the increased demand for both SPF (B-virus, SRV-D, SIV, STLV-1 and SV404ee) and Man' A*01 positive rhesus monkeys. Forty-five SPF females and nine SPF males (nine breeding groups) will added to the colony each year through internal recruitment from CS and SSFS. MHC-typing and selective breeding will be used to increase the production of SPF Mamu- A*01 positive offspring. By year five t program will have supplied 106 offspring including about 30 Mamu-A*01 positive animals. By year 6 or 7, the program should be self-supporting. The CPRC's program will make a significant contribution to advancing AIDS research by providing high quality and healthy SPF rhesus monkeys to NIH-sponsored research programs.